We stayed at iSanook for 2.5 months as we were students in Bangkok. iSanook was, with its friendly and professional staff, great location and modern and well-designed rooms, a second home to us. We really enjoyed staying there.
iSanook has all the facilities you need: pool area with sunbeds and possibilty to order down food from the restaurant, laundromats (30thb/machine), free wifi, entertainment room with huge tv, jacuzzis and sunbeds on the roofs, fitness room, restaurant/bar on the roof.
The district Bangrak is very Thai, with a lot of Thai streetfood/fruit/thai coffee vendors (especially on Rama IV), which we really liked. Also, it is close to Chinatown, Silom, Chao Phraya and the shopping areas are just 5-10 minutes tuk-tuk drive away. MRT station Sam Yan is the closest station.